1. Field of the Invention
The present invention relates to fiber optic sensors and more particularly to fiber optic sensor modules designed for use with remotely located sensor elements.
2. Description of the Prior Art
Optical fibers are rapidly becoming the transmission means of choice for conveying information between two different locations. In most instances optical fibers are thought of in relation to the communications industry in that they provide significantly greater bandwidths and information carrying capacity. However, a new use for optical fibers has been realized with the development of various types of fiber optic sensors.
Fiber optic sensors are becoming an accepted means for measuring and sensing all types of physical and chemical effects. Active and passive sensor elements have been developed and continue to be developed. An article by G. H. Siegel, Jr. entitled "Optical Fiber Sensors in the Life Sciences: Non-Interferometric Approaches", as found in Collection of Technical Papers. Fall 1990, published by Fiber Optic Materials Research Program at Rutgers University, contains an overview of many different types of optical fiber sensors. Unique fiber optic sensor applications are found in the Life Sciences involving in-vivo monitoring of blood gasses, as well as physical parameters such as pressure, temperature and flow and remote chemical and biochemical spectroscopy.
In general, fiber optic sensor elements respond to an optical interference generated by a chemical or physical event. The resulting optical interference is typically a change in optical wavelength, polarization angle, amplitude or rate of modulation. All fiber optic sensors require components for generating the optical signals for the sensor elements and for processing the optical signals generated by the sensor elements. These components are usually located in a separate housing remote from the sensor element which is connected by an optical fiber. In the medical field, a sensor can only be used once and therefore must be manufactured at the least possible cost. The use of such disposable fiber optic sensors is limited by the high cost of reliable optical processing elements.